THE DIELECTRIC RESPONSE OF A DILUTE SUSPENSION OF SEMICONDUCTING PARTICLES

The aim of this note is to draw attention to the interesting electrica l properties of aqueous suspensions of semiconducting particles. The c harge carriers in these particles have a very high mobility, and, as a result, large polarization currents are set up when an external field is applied. For spherical particles this has the effect of causing th e particles to behave like dielectrics with an enhanced permittivity e psilon. The value of the effective permittivity depends on the ratio of the particle radius to the internal Debye length of the semiconduct or. A formula for epsilon is obtained in the case when the equilibriu m charge carrier distribution is uniform over the particle. (C) 1996 A cademic Press, Inc.